I am curious, what are the differences between 2 woods, the same model, but with a weight difference of ~ 5 grams.

My only experience is the vega pro xiom model, a 80 grams wood and one of 84. The 84 was faster and harder (stiff).
1) Is it true for all woods the difference or some heavier can feel more soft than lighter?

2) and where does the diffence of weight come from? more wood? (ie some layers are thicker), or dense wood? or maybe the lighter is easier to say so?

3) Heavier wood, has the extra weight distributed to the handle or to the head of the blade?

want to answer those who have the same wood model, with different weights, to tell me what they think. please do not use the terms 'control', 'feel' that they are pretty vague and do not mean much. I'm intriguing hard / soft, stiff / flexible and speed

I ask that at the moment I use an 83-gram ALC, but the 90 grams are highly appreciated on the net, and I'm curious to what extent I might like a heavier one,